My nearly-null research day was saved by a brown-bag talk by Bob Johnson (UVa, NYU) about Saturn's moons and rings, and what we have learned from the Cassini Mission. The spacecraft takes images but also in-situ spectrometer measurements, so it can measure interplanetary plasma. There are many surprises, including oxygen ions all around, which means (for example) that Titan has a lot of chemical diversity. Johnson's research is about understanding the plasma physics given heating, transport, and chemical processes. The system is very seasonal, as the rings get heated from below, then edge-on, and then above. And there are apparent changes in the plasma near the co-rotation of the magnetic field and the rings.